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US5249064A Expired / Lapsed US ⏱️ 0.0 years remaining

Noise canceller for use in a magnetic reproducing apparatus

Assignee: Akai Electric Co Ltd
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Filing: 1992-09-15
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Granted: 1993-09-28
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Expires: 2012-09-15
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Abstract

Abstract A magnetic recording/reproducing apparatus, which includes: a reproduced level detector for detecting the level of a reproduced signal and a memory for storing the reproduced level detected by the detector; and when recording a video signal, the signal is recorded and reproduced in advance, and this reproduced level is stored in the memory, so that an amount of emphasis of a detail emphasis circuit in a reproducing system and an amount of equalization of an FM equalizer in the recording system can be controlled in accordance with the stored reproduced level; while when reproducing the video signal, the level of a reproduced FM luminance signal is detected by the reproduced level detector, so that an amount of equalization of an FM equalizer, an amount of cancellation of a line noise canceler, and an amount of cancellation of a noise canceler in a reproducing system can respectively be controlled in accordance with the detected reproduced level; whereby the characteristic of a video tape can be controlled in accordance with the type thereof on an apparatus-wide and integrated basis.

Inventors

  • 👤 Tokuichi Minakawa

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-06 08:59
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/79; H04N9/793; H04N9/7933; H04N5/00; H04N5/76; H04N5/91; H04N5/911; H04N5/92; H04N5/923; H04N9/7908; H04N9/80; H04N9/82; H04N9/83

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 156 words
A noise canceller for use in a magnetic reproducing apparatus, said noise canceller comprising: a reproduced level detector for detecting a reproduced level of a reproduced frequency-modulated luminance signal; means for demodulating a luminance signal from said reproduced frequency-modulated luminance signal to provide a demodulated luminance signal; means for extracting noise components from said demodulated luminance signal; a chroma level detector for detecting a level of a reproduced chroma signal; a slice circuit having a slice level which has a variable magnitude for providing an output in which components of said noise components that have levels which are higher than said slice level are removed, said magnitude of said slice level varying so as to decrease with increasing values of said reproduced level of the reproduced frequency-modulated luminance signal and to increase with increasing values of the detected reproduced chroma level; and subtractor for subtracting said output of said slice circuit from said demodulated luminance signal.
Claim 2
Dependent Claim 156 words
A noise canceller for use in a magnetic reproducing apparatus, said noise canceller comprising: a reproduced level detector for detecting a reproduced level of a reproduced frequency-modulated luminance signal; means for demodulating a luminance signal from said reproduced frequency-modulated luminance signal to provide a demodulated luminance signal; means for extracting noise components from said demodulated luminance signal; a chroma level detector for detecting a level of a reproduced chroma signal; a slice circuit having a slice level which has a variable magnitude for providing an output in which components of said noise components that have levels which are higher than said slice level are removed, said magnitude of said slice level varying so as to decrease with increasing values of said reproduced level of the reproduced frequency-modulated luminance signal and to increase with increasing values of the detected reproduced chroma level; and subtractor for subtracting said output of said slice circuit from said demodulated luminance signal.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1996-09-27 1997-03-29 1997-09-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2000-09-27 2001-03-29 2001-09-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2004-09-27 2005-03-29 2005-09-28 $7700.00 Window Closed / Lapsed

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